This is the first installment of 2 articles that discuss the biology and pathophysiology of wound healing, review the role that growth factors play in this process, and describe current ways of growth factor delivery into the wound bed. Part 1 discusses the latest advances in clinicians’ understanding of the control points that regulate wound healing. Importantly, biological similarities and differences between acute and chronic wounds are considered, including the signaling pathways that initiate cellular and tissue responses after injury, which may be impeded during chronic wound healing.

This is the second of 2 articles that discuss the biology and pathophysiology of wound healing, reviewing the role that growth factors play in this process and describing the current methods for growth factor delivery into the wound bed.

Background: Formation of new blood vessels, by either angiogenesis or vasculogenesis, is critical for normal wound healing. Major processes in neovascularization include (i) growth-promoting or survival factors, (ii) proteolytic enzymes, (iii) activators of multiple differentiated and progenitor cell types, and (iv) permissible microenvironments. A central aim of wound healing research is to “convert” chronic, disease-impaired wounds into those that will heal. The problem: Reduced ability to re-establish a blood supply to the injury site can ultimately lead to wound chronicity. Basic/Clinical Science Advances: (1) Human fetal endothelial progenitor cells can stimulate wound revascularization and repair following injury, as demonstrated in a novel mouse model of diabetic ischemic healing. (2) Advances in bioengineering reveal exciting alternatives by which wound repair may be facilitated via the creation of vascularized microfluidic networks within organ constructs created ex vivo for wound implantation. (3) A “personalized” approach to regenerative medicine may be enabled by the identification of protein components present within individual wound beds, both chronic and acute. Clinical Care Relevance: Despite the development of numerous therapies, impaired angiogenesis and wound chronicity remain significant healthcare problems. As such, innovations in enhancing wound revascularization would lead to significant advances in wound healing therapeutics and patient care. Conclusion: Insights into endothelial progenitor cell biology together with developments in the field of tissue engineering and molecular diagnostics should not only further advance our understanding of the molecular mechanisms regulating wound repair but also offer innovative solutions to promote the healing of chronic and acute wounds in vivo .